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        <h2>
          <span class="refentrytitle">trfilter</span>
        </h2>
        <p>trfilter — 
      Streaming partial track filtering.
    </p>
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      <div class="refsect1">
        <a id="idp159318288"></a>
        <h2>Description</h2>
        <p>
      The <span class="emphasis"><em>trfilter</em></span> opcode takes an input containg a TRACKS pv streaming signal (as generated,
      for instance by <span class="emphasis"><em>partials</em></span>) and filters it using an amplitude response curve stored in
      a function table. The function table can have any size (no restriction to powers-of-two).
      The table lookup is done by linear-interpolation. It is possible to create time-varying
      filter curves by updating the amlitude response table with a table-writing opcode.
    </p>
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      <div class="refsect1">
        <a id="idp159385360"></a>
        <h2>Syntax</h2>
        <pre class="synopsis">fsig <span class="command"><strong>trfilter</strong></span> fin, kamnt, ifn</pre>
      </div>
      <div class="refsect1">
        <a id="idp159387568"></a>
        <h2>Performance</h2>
        <p>
      <span class="emphasis"><em>fsig</em></span> -- output pv stream in TRACKS format
    </p>
        <p>
      <span class="emphasis"><em>fin</em></span> -- input pv stream in TRACKS format
    </p>
        <p>
      <span class="emphasis"><em>kamnt</em></span> -- amount of filtering (0-1)
    </p>
        <p>
      <span class="emphasis"><em>ifn</em></span> -- function table number. This will contain an
      amplitude response curve, from 0 Hz to the Nyquist (table indexes 0 to N). Any size is
      allowed. Larger tables will provide a smoother amplitude response curve. Table reading uses
      linear interpolation.
    </p>
      </div>
      <div class="refsect1">
        <a id="idp159391968"></a>
        <h2>Examples</h2>
        <p>
      Here is an example of the trfilter opcode. It uses the file <a class="ulink" href="examples/trfilter.csd" target="_top"><em class="citetitle">trfilter.csd</em></a>.
      </p>
        <div class="example">
          <a id="idp159393744"></a>
          <p class="title">
            <strong>Example 943. Example of the trfilter opcode.</strong>
          </p>
          <div class="example-contents">
            <p>See the sections <a class="link" href="UsingRealTime.html" title="Real-Time Audio"><em class="citetitle">Real-time Audio</em></a> and <a class="link" href="CommandFlags.html" title="Csound command line"><em class="citetitle">Command Line Flags</em></a> for more information on using command line flags.</p>
            <pre class="programlisting">
<span class="csdtag">&lt;CsoundSynthesizer&gt;</span>
<span class="csdtag">&lt;CsOptions&gt;</span>
<span class="comment">; Select audio/midi flags here according to platform</span>
-odac     <span class="comment">;;;realtime audio out</span>
<span class="comment">;-iadc    ;;;uncomment -iadc if realtime audio input is needed too</span>
<span class="comment">; For Non-realtime ouput leave only the line below:</span>
<span class="comment">; -o trfilter.wav -W ;;; for file output any platform</span>
<span class="csdtag">&lt;/CsOptions&gt;</span>
<span class="csdtag">&lt;CsInstruments&gt;</span>

<span class="ohdr">sr</span> <span class="op">=</span> 44100
<span class="ohdr">ksmps</span> <span class="op">=</span> 32
<span class="ohdr">nchnls</span> <span class="op">=</span> 2
<span class="ohdr">0dbfs</span>  <span class="op">=</span> 1

gifn <span class="ohdr">ftgen</span> 2, 0, <span class="op">-</span>22050, 5, 1, 1000, 1, 4000, 0.000001, 17050, 0.000001 <span class="comment">; low-pass filter curve of 22050 points	</span>

<span class="oblock">instr</span> 1

kam  <span class="opc">line</span> 1, p3, p4
ain  <span class="opc">diskin2</span> "beats.wav", 1, 0, 1
fs1,fsi2 <span class="opc">pvsifd</span>	ain, 2048, 512, 1		<span class="comment">; ifd analysis</span>
fst  <span class="opc">partials</span> fs1, fsi2, .003, 1, 3, 500	<span class="comment">; partial tracking</span>
fscl <span class="opc">trfilter</span> fst, kam, gifn			<span class="comment">; filtering using function table 2</span>
aout <span class="opc">tradsyn</span> fscl, 1, 1, 500, 1			<span class="comment">; resynthesis </span>
     <span class="opc">outs</span> aout, aout

<span class="oblock">endin</span>
<span class="csdtag">&lt;/CsInstruments&gt;</span>
<span class="csdtag">&lt;CsScore&gt;</span>
<span class="stamnt">f</span>1 0 8192 10 1

<span class="stamnt">i</span> 1 0 4 1
<span class="stamnt">i</span> 1 5 4 0	<span class="comment">;reduce filter effect</span>
<span class="stamnt">e</span>
<span class="csdtag">&lt;/CsScore&gt;</span>
<span class="csdtag">&lt;/CsoundSynthesizer&gt;</span>
</pre>
          </div>
        </div>
        <p><br class="example-break" />
    </p>
        <p>
      The example above shows partial tracking of an ifd-analysis signal and
      linear additive resynthesis with low-pass filtering. 
    </p>
      </div>
      <div class="refsect1">
        <a id="idp159398576"></a>
        <h2>Credits</h2>
        <p>
      </p>
        <table border="0" summary="Simple list" class="simplelist">
          <tr>
            <td>Author: Victor Lazzarini;</td>
          </tr>
          <tr>
            <td>February 2006 </td>
          </tr>
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        <p>
    </p>
        <p>New in Csound 5.01</p>
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